Yaw 3 VR Motion Simulation Rig

Introduction

This is the Yaw 3 motion simulator from YawVR.  It’s designed to give you a big leap in VR immersion when using flying and driving simulators – or really any game that involves motion in virtual reality – think roller coasters, kayaks, etc.  VR is already an amazing immersive experience – it’s wild to fool your brain into believing you’re somewhere else with just sight and sound – so adding motion to a vehicle-oriented VR experience can take the immersion even further.

While motion simulators can’t replicate the true forces acting on your body in a real driving or flying experience, they are capable of generating up to six degrees of motion – rotational movement: pitch, roll, yaw and translational movement: heave (up/down), sway (left/right) and surge (forward/backward).

The Yaw 3 is an interesting design built on a compact base that can freely rotate in the yaw direction (rotating left/right without limit), provide 40 degrees of roll (tilting left/right 20 degrees) and 70 degrees of pitch (tilting forward/back) – and it can do so very quickly: 160 degrees in a second for roll and pitch.  It also supports generating vibrations to help feel road surfaces and engine vibrations.

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Assembly

Unfortunately, it hasn’t been a simple plug-n-play experience to get the Yaw 3 set up.  Unlike some other folk, my unit arrived without any apparent shipping damage. Not surprisingly, the unit does require some assembly.  Setting up the Yaw base platform and connecting the roll and pitch component is fairly straightforward but they could use more detail in their assembly video.  (At the time of my order in early November 2024, there was no written instructions.). For example, while connecting the drive belt for the pitch axis they tell you to make sure it is tightened appropriately without saying how tight or loose it should be.  This would prove to come up again later.

Central Mount – Warped Base

When I went to install the central vertical mount for the table, I discovered that the steel base of it was warped in such a way that it was impossible to even start to fit all four bolts through the holes into the leg extension below.  While waiting to hear back from their support person via email (there’s a nine-hour time zone difference), I tried using a mallet to flatten out the base.  I was able to flatten it out just enough to start the bolts but not far enough to reach the threads in the leg extension.  The response from YawVR’s support person was that this deformed base was normal and not a problem.  After I followed up explaining that I couldn’t even start to thread it, even after trying to bash the base more flat, they suggested I try longer bolts.  I did go out and find some longer bolts and this did work.  I was a little nervous about forcing the base to conform by threading the bolts to the support (fearing the threads would break), but it ultimately did work and de-warped the central mount’s base to fit.  That does raise the question of how the shorter provided bolts were expected to work and whether my central mount’s base was actually not manufactured wrong.

Central Mount – Orientation and Position

Another detail that wasn’t spelled out in the setup video was the orientation of the central mount.  It was not symmetrical.  The mount has a spring resisting movement in one direction and the cutout allows it to rotate farther in one direction than the other.  The video showed the shorter end of the cutout facing towards the seat but after trying this I decided it was a bad idea because with added weight of a driving wheel on the table, it was far too easy to mistakenly let slip the table to drop very quickly and smash the foot plate (and any pedals installed there).  I decided to flip it around and secure the central mount so that the shorter end of the movement would face away from the seat and prevent it from falling all the way.  Later on I also decided to give myself more leg room for getting into and out of the seat by moving the mount to the set of bolt holes farther away from the seat.  (More on that later.)

Damaged Threads

While continuing to assemble the unit, I went around checking that every bolt along the assembled leg extension and footrest was secure.  I was doing this manually with an Alan (hex) wrench, not a power tool, and yet one of the bolts broke free – the internal threading in one bolt hole of the leg extension broke off and fell out.  I contacted support over this and after the usual back-and-forth email exchange, they’ve promised to send a replacement.  (That’s currently on hold waiting for something else.)

Foot Plate Adjustability

The angle of the foot plate is adjustable with a series of bolt holes and a pair of hex head bolts.  I swapped these out for a knobbed bolt that can be removed without tools.  The length of the leg extension that supports the foot plate is also adjustable but not easy to get to.  It has a few inches of leeway that it can be slid in or out when securing it to the frame under the seat but it’s not accessible without removing the seat entirely.  This is too much of a hassle to go through to adjust it for different guest users.  I think they should rework this design to make it easily adjustable for riders of different heights.  It might be enough to just invert the placement of the brackets and bolts so that they’re reachable from under the seat with knobbed handle bolts.  Since that isn’t an option, I decided to not use the full extension of the leg rest despite my height (not quite 6’4″ or about 192 cm) to more likely accommodate shorter riders.

Squealing Noise from Roll Axis

After assembly, I quickly noticed that my Yaw 3 would emit a squealing noise when you rolled it near the left end of its roll axis.  I could reproduce this easily just by manually rolling it to the end of the axis while the power was off but it would also creak like this under power.  I could see that two of the three rollers on the front side never make contact with the roll axis and one roller on the back side (the leftmost one) was enduring a lot of pressure against the roll axis.  Originally I thought that perhaps the noise was coming from this one roller under pressure.  Here’s a video recording of the problem before it was figured out.

After more days of back and forth emails with YawVR support (different time zones so always a day or two for each response/reply) and after chatting with folks on the Official YawVR Discord forum, I eventually realized that one of the rollers underneath was rubbing against the roll axis belt.  My belt is not quite centered between the two rollers on the left end of the roll axis (but it’s fine on the right end).  I could see it was starting to get damaged just from me manually rolling the seat to figure out where the squeal was coming from.

In the meantime, I got another response from YawVR Support where they suggested, “apply some WD40 maybe on both sides of the belt where the sound comes from. Please let me know if it helped or not.” I pushed back on that suggestion as WD-40 is really a solvent and not a good idea to try to use as a lubricant or to eliminate squeaks.

Once I pointed out that the belt was rubbing, they directed me to loosen the roll belt by loosening the screw on the belt attachment point enough to allow a pencil to be slipped between it and the roll axis. To do this, they explain that “you need to completely remove the screw on one side, and then put the screw back, and when you place the belt back, you don’t need to turn it completely in, just so long that it you can fit a pencil there.”

This did alleviate the squealing noise up (at least up until just the last few millimeters) by apparently allowing the belt to relax and sit just barely far enough away from the one roller.  It’s good that the belt is no longer rubbing on the roller but I still wonder about why two rollers on the front side of the roller axis don’t make contact at all – perhaps my roller axis is out-of-alignment or warped?  YawVR support says it was designed this way “so there wouldn’t be any room for unnecessary wobbling which could cause damages.”

Another outstanding concern is that one of the rollers below and next to my roll axis belt doesn’t sit directly under the roller axis and may eventually fail. As others are discussing on the YawVR Discord server, there seems to be a flaw with how these rollers are supposed to work as several folks have had the rubber portion of the roller come off the wheel underneath.

Anyway, the upshot on the squealing from mine was that loosening that tension screw at the top of the belt allowed the belt to move just enough away from the roller that it no longer rubbed (and squealed) except for the last few millimeters at the end of the roll axis. So I guess my belt was too tight – or it’s not quite centered.

Seat Selection and Installation

As for the seat… I opted not to buy the YawVR seat with the Yaw 3 because they said you could use your own gaming seat, I wasn’t into the idea of LED lighting on the seat and I figured it might save a bit on shipping to just order a seat here in the U.S. anyway. Well… oops.  After ordering the Yaw 3 without the seat and starting my search for a seat, I discovered that wasn’t such a simple purchase.  Lots of gaming seats get bad reviews for being junk, many gaming seats are actually rather small (again, I’m pretty tall) and many are so confining that wearing a VR headset while sitting in them would be a problem – keeping you from being able to look around.  After a really long search over many days, I eventually settled on the GT Omega RS12 – which would ship from Europe anyway and would have to be backordered.  It’s a nice seat though and plenty tall.  It’s also larger width-wise for folks who might need that extra room.

The seat did eventually arrive some week or so after I got the Yaw 3 and that’s when I discovered that when YawVR said you could use your own gaming seat, they didn’t mention that you would need to fashion your own mounting bracket.  Oh boy.  Lots more online searching until I eventually settled on trying a couple of heavy, 5mm thick, steel “mending brackets”. (affiliate link)  This was followed with many days of learning better techniques for drilling through thicker steel, getting more supplies (titanium step bits, water-based cutting fluid for drilling, sets of grade 8 bolts and nuts), more problem solving like needing to find strong spacers to leave enough clearance for the seat’s provided slider mechanism to work, etc.

Seat Slider Is a Bad Idea

Eventually though, I did succeed in getting the GT Omega seat and slider mounted to the Yaw 3.  Soon after, I injured my hand by mistakenly trying to use the slider while seated in the rig.  The idea with using the included slider mechanism on the chair was that it would better accommodate riders of different heights since the leg extension to the foot plate is at a fixed distance once you finish assembly.

I found trying to use a slider with the Yaw 3 was problematic for a bunch of reasons:

  1. First off, it was dangerous.  If you reach down and release the slider while you’re sitting in the seat, you immediately get launched forward with full force to the limit. I crushed my knuckles against the center mount the first time. I added a hard stop on the slider as a safety measure and then tried to remember not to use it while sitting but I still managed to forget some days later.  At least I didn’t hurt myself the second time but because of how the seat can often be leaning forward when you’re adjusting things, you just get launched forward uncontrollably.  You simply have to adjust the slide position while not seated.
  2. It raises your seating position both by the height of the slider mechanism itself and the additional spacers you’ll need to leave enough room for the slider bar to be usable under the seat frame.  This added height made it that more difficult to climb into the rig (it’s already on a raised platform) and more difficult to position the center mount table comfortable over my knees.
  3. It messes up the weight balance of the rig to move the seat position. You want to counter the weight of the leg extension and any peripherals on the center mount table or the foot plate by placing weights behind the seat back so that the pitch motor can operate smoothly. Sliding the seat forward or back shifts your body weight forward or back and dramatically screws up how you’ve balanced things.
  4. Once you’ve set up your motion compensation software based on the Yaw 3’s built-in tracking or on a separate fixed tracker, you’re messing up the numbers on your saved configuration that tells how far the headset is from the center of rotation for all three axes (pitch, roll and yaw).  (This might not be an issue if you’re using YawVR’s InfuseVR software and your headset’s VR controller.  Not sure about that.)

Once I discovered the impact of the slider, I ended up removing the seat slider – which meant I had to go and make new holes in my custom brackets so I could still mount the chair – I also mounted a bass shaker underneath (more on that later).

Repositioning Center Table Mount

I decided to move the center table mount to the second set of bolts farther away from the seat because it was difficult to maneuver my legs around  it getting in and out of the chair. Now the chair mount is farther away but angled more towards the seat so there’s more room getting in and out.  As a bonus, it’s easier to position the driving wheel farther away for my longer arms vs someone else’s. It’s very possible that the central mount position was only a problem because I think my non-YawVR seat (a GT Omega RS12) is larger all around: I suspect it has a taller seat back as well as a deeper and wider seat cushion.

Balancing Pitch Axis with Weights

As I mentioned before, you need to balance the whole thing with weights added behind the seat back so that the pitch motor can operate smoothly.  At the time of my purchase, there was nothing in the setup instructional video about this weight balancing but it’s mentioned in the forums and by other users and the Yaw 3 has a dedicated space behind the seat to place circular weights.  Strangely, the provided bolt to hold the weights in place doesn’t include a spacer to keep any weight rings in place.  (Someone has provided a 3D-printer model [need link] to make one though.)

I’m currently using scuba diving soft bag weights totaling 25 lbs (11.3 kg). My Logitech G Pro wheel and pedals are heavy but I did remove the pedal base to help. The rig only balances when I’m sitting in it, otherwise it rests forward. Choosing not to put the foot rest at its farthest extension also helps as the farther the distance any weight is from the center of rotation, the more of an effect it has.  YawVR should really make the leg extension of the foot plate adjustable without having to remove the seat.

👉 So, in short, I don’t recommend trying to use a slider but I do recommend moving the center mount farther away and angling it as needed for reach and to give your legs and knees more room, as you can see in these pictures:

 

Mounting Controllers on the Side Rails

The Yaw 3 now includes a 15 degree angle seat adapter which has the benefit of providing more downward pitch range by taking it from the upward pitch – which is still plenty steep.  One side effect of this adapter is that it makes the optional side rails both too low and angled badly relative to the seat.

I did a bunch of hunting online and ended up finding these 3-axis joint mounts on Amazon (affiliate link) which raise up the mount and provide the ability to angle them as you wish.  Unfortunately they’re only available in white so I had to paint them black (plus a matte clear coat). I made a couple of mounting plates out of MDF plywood to accommodate my Logitech X52 flight stick and throttle:

   

Later, when I upgraded to a VKB joystick and throttle, I used the mounting plate that came with the side rails and made a mounting block out of solid wood for the joystick base:

   

Central Table Mount Accessories

 

Lots more info to come…

Many Peripherals

Lots of peripherals to discuss…

Accessories (includes affiliate links)

Controllers

  • VKB Gunfighter IV joystick grip and base
  • VKB STECS throttle
  • Logitech X52 Pro H.O.T.A.S. (stick and throttle)
  • Logitech Flight Yoke, Pedals and Throttle Quadrant
  • Logitech G Pro Racing Wheel w/direct drive force feedback
  • Logitech G Pro Racing Pedals w/load cell brake

VR Headsets

  • HP Reverb G2
  • Apple Vision Pro

Software Setup

  • YawVR’s Game Link
  • VirtualHere wireless USB support
  • Infuse VR vs. ALVR
  • OpenVR vs OpenXR
  • OpenXR Motion Compensation
  • OpenComposite
  • SteamVR vs Windows Mixed Reality

Troubleshooting – Loss of Motion Control

While testing and tweaking a new profile for MSFS 2024 for a couple of hours, I started to encounter this issue where my Yaw 3 would get stuck in a rolled-to-the-right position. All it would take would be to bank to the right for a few seconds but then when I’d level out or roll to the left, I would still be stuck in the rolled to the right position. And yet the Game Link Input Monitor would show a level position for output.  Sometimes if I rolled in the opposite direction and held it there long enough it would usually eventually start to come back but not always. Engaging the parking mode would actually lower the pitch and leave the roll axis tilted.

Skipping over most of the intermediate troubleshooting, I eventually figured it out by testing with and without my weight in the seat and using YawVR app’s manual control.  Turns out it was just the power level setting. I had turned it way down to 10% in the midst of my testing MSFS to see if there was a way to mitigate how the Yaw 3 will stop at a target roll position so abruptly that the chair will bounce about. (At least it does so with aggressive maneuvers like in an FA-18 military jet.)

👉 So yeah, 10% was not enough to move me and the chair out of the right rolled position. Just bumping the power level back up to 30% fixed it.

Fine-Tuning a Profile for Microsoft Flight Simulator 2024

Several of us are still working together to develop a better motion control profile for MSFS 2024 here.  When we get a pretty good solution, I’ll post the details here.

Demonstration Videos

The fun stuff!

Somebody asked for a test of the range of hertz and amplitude that the Yaw 3 can generate.  I put this video together to get an idea of what the different values produce – and was taken aback at how violently it can move just when generating vibrations:

Much more to come…